使用for循环移动UIView [英] Moving UIView with a for loop

问题描述

我正在尝试移动一个很小的UIView.我的for循环只是将UIView向下移动了100点.

I am trying to move a UIView, which is small. My for loop just moves the UIView down 100 points.

除了在循环完成之前它不会移动之外，这是可行的.

This works except it doesn't move until the loop is finished.

我尝试设置

[self.view setNeedsDisplay]和[myView setNeedsDisplay]，我还将该函数放在了nstimer和nsthread中，如下所示

[self.view setNeedsDisplay] and [myView setNeedsDisplay], I have also put the function inside nstimer and nsthread, like seen below

[NSThread detachNewThreadSelector:@selector(doStuff) toTarget:self withObject:nil];

和

[NSTimer scheduledTimerWithTimeInterval:1/15
     target:self selector:@selector(doStuff)
         userInfo:nil 
     repeats:NO] ;

但是它只是不动画".

But it just does not "animate".

每次移动视图后，我都会进行sleep(1);但还是一无所有.

After each move of the view, I do a sleep(1); but still nothing.

希望任何人都可以帮助我.

Hope anyone can help me.

推荐答案

您的for循环会阻止视图的实际重绘，该重绘发生在运行循环中，当视图的drawRect被调用时.您有三个选择(还有更多选择).

Your for loop blocks the actual redrawing of your view, which happens in the runloop, when your view's drawRect gets called. You have three options (and many more).

@Darren建议了两个.另一个方法是调用performSelector:afterDelay，并传入将视图移动100像素(for循环的内部)的例程.在该例程的结尾，调用performSelector:afterDelay:重新排队下一个调用.我更喜欢使用计时器.

Two were suggested by @Darren. Another is to call performSelector:afterDelay passing in the routine that moves the view 100 pixels (the innards of your for loop). At the end of that routine, call performSelector:afterDelay: to requeue the next call. I prefer this to using a timer.

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